Winding bobbin



)May 10, 1927.-

H. V. N. SNYDER I WINDING BOBBIN Filed Jan. 19, 1927 INVENTOR MIKEY 4/11 mm A'ITORNEY I Patented May 10, 1927.

UNITED STATES PATENT OFFICE.

HARRY V. N. SNYDER, F CLIFTON, NEW JERSEY, ASSIGNOR TO THE MANHATTAN RUBBER MFG. COMPANY, A CORPORATION OF NEW JERSEY.

My invention relates to a winding bobbin which is particularly suitable for receiving threads of rayon (artificial silk) wound thereon. The drawings show an embodiment of the invention which I now prefer, although I realize that it may be embodied in other forms.

Fig. 1 is a perspective view of the bobbin, and in Fig. 2'is a detail section greatly enlarged. A winding bobbin which is particularly suitable for receiving threads of delicate rayon, and which shall embody the desirable features and avoid those things which have been found in practice to be objectionable, has been difficult to obtain. Rayon is made from a cellular structure, usually Wood, which has been dissolved and suitably treated. In its liquid and somewhat viscous con dition, it is squirted through extremely minute holes in a head, usually of platinum, into a bath which immediately causes the fluid to set,for1 ning a minute filament like a single filament of natural silk. A number 2.1 of such filaments as they come from the fixing bath are collected into a thread and then wound upon a bobbin. The filaments are extremely delicate, and any undue tension or sudden jar is likely to break them, either before becoming completely set in the bath or when on the bobbin. -As the threads are wound on the bobbin, its diameter naturally increases and if this exerts too much tension, the filaments, or some of them, will be broken. They carry some acids or alkalis, or

. both, and the bobbin must be unaffected by them. A metal bobbin although desirable from a mechanical standpoint, is undesirable from a practical standpoint due to the acids and alkalis which not only affect the bobbin itself but the metal from the efiects of the acid solution will react upon the rayon threads and discolor or otherwise injure them. Many bobbins have been used, such as various special, metals, rubber, bakelite, metal with a coating ofbaked enamel and others. All of these have many very good characteristics, but do not give entirely satisfactory service because they lack one or more necessary characteristics to 'work satisfactorily through the entire processf Wooden bobbins, such as used for winding cotton or natural silk, have been tried but are not suitable. It is desirable that the air be allowed to penetrate freely through the bob- 'sist the distortion.

WINDIN G BOBBIN.

'Application filed January 19, 1927. Serial No. 162,016.

b1n to the interior of the mass of rayon wound thereon. It therefore should be hollow and full of perforations. It should be as light as possible and therefore thin. Thin metal is thus suggested, but this has extremely undesirable characteristics. Sheet iron, for example, is attacked by the acids and alkalis present, and the attacked portions react upon the rayon threads .and discolor or otherwise injure them. It is a 5 somewhat difficult and expensive job to form perforations through metal which shall be free from burrs and roughnesses which are likely to injure the filaments.

The rayon filaments contract somewhat 7 after they are set in final form and, while the individual filament is weak, collectively this contraction exerts a considerable tension longitudinally of the thread. The bobbin should therefore be so made that it will re- Bobbins that have the mechanical strength do not have acid and alkali resistance and vice versa.. A hard rubber bobbin made entirely of rubber will 1 resist the acid and alkali but due to the naso ture of the material when vulcanized rock hard is brittle and will chip and crack, and it will also soften up when run through the heated alkali and acid solutions, which renders it unsatisfactory as the tension of the 35 rayon threads during the drying process distorts the bobbin out of shape, causing wind ing difliculties, difliculty in removing the bobbin and other disadvantages.

A metal bobbin covered with baked enamel 9 was tried, but this is objectionable for some of the above reasons. It is not easy to make,

especially with a thin body, where even the walls of the perforations have to be protected, and when it cracks or chips as it does it is open to the same objection as an allmetal bobbin.

Asuccessful bobbin suitable particularly for winding rayon therefore embodies fea-- tures which are diverse and have been thought to be impossible of practical accomplishment in a unitary structure. By my invention I have, however, been able to overcome the above objections, while at the same time retaining the desired vantage. r

I'have shown in the drawin a cylindrical bobbin A which has a body of thin metal such as sheet iron or aluminum and which' is therefore capable substantially of resist-. no

features of ading the distortion due to the contraction of the threads and the winding tension but can yield slightly and is elastic enough. to spring back to form. It is. formed with a multitude of perforations C which communicate with its hollow interior. The exterior and interior surfaces are entirely covered with a thin layer of rubber which is resistant to acids and alkalis. This rubber is preferably applied by placing around and in contact with its exterior surface, and also with its interior surface, a thin layer of unvulcanized rubber, e. g. 5nd of an inch. It may then be put into a vulcanizer which exerts pressure both radially inward against the outer layer and radially outward against theinner layer of rubber. This may be done by one of the well known vulcanizers. lit is not necessary to describe this more particularly, as rubber manufacturers are familiar with such process.-

The pressure exerted forces the rubber layers into intimate contact with the exterior and interior surfaces of the metal body at every point and holds it there while being vulcanized. It also forces the rubber into the holes but leaves a thin diaphragm across each hole. This diaphragm may then be removed by a suitable punch or drill, small enough not to touch the walls of the holes, that is, so as to leave a film of rubber completely enclosing and covering the wall of the hole in the metal body.

A fragment is illustrated (greatly enlarged) in Fig. 2. In this the metal body B, with the hole therein as-shown, is illustrated as covered with the thin rubber layers D, D. .lt will be observed that the wall E of the hole is also completely covered and protected by the rubber. The diaphragm of rubber is formed at F, which is, as shown, removed by the punch or drill above mentioned. I

As shown in Fig. 1, the holes are preferably arranged in patterns, such as a row or a combination of rows, which repeat themselves regularly all around its periphery. This'allows ofvthe use of a gang punch or drill for removing the rubber diaphragms originally closing the holes.

The completed bobbin has all of the desirable characteristics above specified and none of the objectionable features. As a whole, it is resistant to compression tension. At the same time there are no metal parts exposed to the action of the acids and alkalis,

even the walls of the holes. The filaments therefore cannot be injured from this cause.

Also as the bobbin has a multitude of perforations throughout its body portion, any thread will therefore pass across a large number of perforations in being laid around the periphery. Airmay circulate through the bobbin and into the mass of rayon thereon.

The vulcanization should be carried beyond the point where the rubber is soft like that of a pencil eraser, and yet stop short of so called rock-hardness which would render it brittle. When this is done with a thin rubber layer, for example one thirty-second of an inch in thickness, a surprising result is attained. Vhen the bobbin is smoothed or polished by friction in the ordinary manner, or even after it attains this relatively polished surface by use, the body of the rubber film underneath the exterior skin will be" found to be somewhat yielding so that it can be indented by pressure of a sharp inst-rument like a pin, but yet is extremely tough and resistant so that it is practically impossible .to crack or chip it in the hard usage to which such bobbins are subjected, even by sudden shocks such as when the bobbins are dropped onto a hard floor or thrown together in a receiving box. At the same time the outer surface has the appearance of a rock-hard structure and yet has such a high molecular cohesion that it is practically impossible to chip or crack it. Whether these results are due to the fact that the bobbin hasa thin metal body overlaid with thin films, or to the heat generated by the friction or to air oxidation, or to a combination of these and other causes, I have not determined. However, the result is a bobbin completely covered with rubber and which is as a whole resilient to ordinary distortion and shocks, and yet is so extraordinarily tough that it will not crack or chip, which has long been sought in this art.

\Vhat I claim is:

A winding bobbin suitable for having threads of rayon wound thereon, comprising a hollow, thin, slightly resilient but substantially distortion-resisting body having a multitude of perforations through its surface and communicating with its hollow interior, the exterior and the interior of the winding surface of the bobbin being entirelv covered with a thin layer of rubber resistant to acids and alkalis and vulcanized to such a degree between softness and rock-hardness as renders the covering material somewhat yielding but tough and substantially resistant to cracking or chipping and with an exterior surface of high molecular cohesion.

Signed at New York, N. Y., this 18th day of January 1927. I

HARRY V. N. SNYDER. 

